Contact bank of switches and cabling arrangement between switches in automatic telephone systems



Jan. 27, 1948. BAKER CONTACT BANK OF SWITCHES AND CABLING ARRANGEMENT BETWEEN SWITCHES IN AUTOMATIC TELEPHONE SYSTEMS 2 Sheets-Sheet 1 Filed March 6, 1945 INVENTOR GEORGE THOMAS BAKER ATTORNEY Jan. 27, 1948. G. T. BAKER 2,435,025

CONTACT BANK OF SWITCHES AND CABLING ARRANGEMENT I BETWEEN SWITCHES IN AUTOMATIC TELEPHONE SYSTEMS 7 Filed March 6, 1943 2 Sheets-Sheet 2 IN VENTOR GEORGE THOMAS BAKER ATTORNEY Patented Jan. 27, 1948 :CONTACT OF SWITCHES AND CABLING ARRANGEMENT BETWEEN SWITCHES PHONE SYSTEMS George Thomas Baker, Liverpool, England, as-

-signor, by memo assignments, to Automatic Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware IN AUTOMATIC TELE- Applica tion'March 6, 1943, Serial No. 478,241 "Iri Great Britain April- 20, 1942 17 Claims. (01. 179- 2752) rangements between switches in automatic telephone systems. The invention relates to' a novel method of cabling and mounting-switches-in an exchange which becomes readily possible when employing contact banks/of the type described in applicant's PatentNo. 2,402,232, granted June 18, 1946, although thesemounting arrangements could be appliedto switches having different constructions of contactbanksas-will be-readily appreciated.

According to .afeature of the invention bank multipling arrangements -for a telephone exchange comprisesets of vertical contact members, each set being available in common to'a group of selector switches arranged vertically over each other, different sets of verticalcont-act members terminating on different levels, horizontal cablesor runways being provided forinterconnecting switches whose vertical contact members terminate on the-same level.

According to a further feature of the invention an exchange layout comprises sets of vertical contact'members each set beingavailable-in common to a group of selector switches arranged vertically'overeach other, vertical driving shafts by which the switch-operating members of each group are operated substantially in a horizontal plane and horizontal runways for supportingintercommunicating cables between sets-of vertical contact members.

The invention will be better understood from the following descriptionof one method of carry ing it into effect, reference being had to the accompanying drawings which correspond to similar figures in my copending application No. 478.245, filed March 6, 1943, now Patent No. 2,402,232, dated June 18, 1946, in which is disclosed a full description of the selector mechanisms and circuits, selector bank construction, and'cabling and mounting arrangements for a new and improved automatic telephone system with which the present invention has direct association.

Referring now to the drawings, Fig. 1 shows a perspective part view of a rectilinear continuous bank showing themetal strip multiples and the precious metal contacts, a desired connection being effected by the appropriateoperation of cordless contact-operating members conveniently referred to hereinafter as wiper arms.

Fig. 2 shows a front elevation of exchange mounting uprights, one of which is equipped with two twenty-selector bank multiples and associated selectors, another with two twenty-selector 2 bank multiples only, while the remainder are shown in various stages of assembly.

As so much of the new telephone system according to the present invention is concerned with a special form of contact bank, a description will first begiven of the construction of a preferred form of bank according to the invention.

A bank is formed by continuous strips 23 running the full length of the predetermined multiple and as shown in the part view of Fig. 1 these are clamped at opposite sides of selectors to form fixed contact members the intervening space between the clampings forming the bank contacts for one selector. At the end of the multiple it will be understood that the strips 23 are fanned out to form wiring tags. That part of the bank multiple allocated per selector will subsequently be referred to as a selector bank so that Fig. 1 may be described as showing a part view of two selector banks in each of which are included three'levels of two conductors each. A level of one bank is moreover assumed to have been broken away in order moreclosely to illustrate its construction. Each bank will be preferably of the point type, that is to say, with ten levels of ten sets of contacts, each set of four contacts being formed on four strips and four combs 24; on each level there may be provided in addition the usual eleventh step set of contacts for overflow busy indication purposes.

A multiple will usually comprise twenty such banks assembled together one above the other, the necessary multipling being inherently performed by virtue of the use of continuous strips 23'which'connectwith the outgoing trunks. The connecting function of the ordinary selector wipers and cords'is takenby a set of comb plates 24 one 'of'which'is provided for each row of strips, conveniently referred to as a level, of each bank and having fingers 26 aligned with the various bank strips. Each finger of a comb plate such as 24 forms a movable contact member. All bank contacts are made of precious metal such as silver, and tomakethis a commercial proposition all the silver/base metal junctions are made by rolling, this rolling operation being carried out in the stock before blanking.

Each row of contact members in a bank is separated from its neighbour by an insulating platesuch as I2 (Fig. 1) of a length equal to that of the comb plates and of a thickness of say 50 mils to reduce possible cross tank to a minimum and at the same time to give ample room in the level for the insertion of the wiper arms. Since each trunk strip will be clamped in each of the twenty banks through which they pass, it is not considered necessary to provide clamping bars which extend through the banks.

Considering now the question of exchange mounting requirements, the exchange construction usually consists of horizontal shelves mounted in vertical racks, the multiples extending horizontally along the shelves and then cabled in a vertical direction and the cabling extending from rack to rack at a high level so as to permit of a passageway between the racks. By means of the invention (see Fig. 2) it is possible to replace the horizontal bank multiple of the shelf by a vertical bank multiple such as 90 and to have horizontal runways 9| 92 and 93 supported by uprights such as 94 and 95 for carrying the cables at different levels. It may be necessary in the case of the lowest cable to raise it so as to clear a passageway, but by arranging the uprights in a continuous linear formation so that there is no passageway between uprights the whole of the cabling may be horizontal, that is to say, by means of the invention it is possible either to considerably reduce vertical cabling or to eliminateit entirely and in any event it opens up large possibilities of designing the layout of an exchange in an entirely different manner than has been hitherto possible. For instance the uprights may be arranged continuously along one, two or three sides of a foursided room. or they could, if the room has a curved wall, be arran ed to follow the curve.

Owing to the fact that the new selector requires considerably less space than existing ones the cablin should receive spec al consideration. Cabling will conveniently be carried out at three levels, say 4'0"; 7'3"; 10'6" from the floor respectively. The hei hts correspond to the top of the three 20 point bank multiples, and accordin ly the wiring from the multiple tags can drop strai ht into the runway. The incoming wires either rise to the runway above or drop to the one below dependent on their final destination. Thus most of the exchange wiring is already terminating virtually in a runway and the remainder reaches it by a very direct route.

These main runways form the basis of the exchan e. They are carried solidly across suites of say five upri hts each and the end su ports for which should be wherever possible built into the building. In any case the suites should follow the main run of the building's steelwork.

The u per two runways 92 and 93 will be carried direct from suite to suite in their own plane whenever necessary but the lower one will only be allowed to connect the wiring side of two back to back suites. In all other cases cables will be carried up to the next runway above to cross aisles etc. It should be noted however that two su tes of five uprights each will accommodate 3000 selectors, one of which is desi nated 95, and which will be enough for most exchanges.

To a large extent the exchange can be cabled prior to placing in position the uprights and switches provided that separate supports are provided for the runways, thus allowing installation and manufacture to proceed to a certain extent simultaneously. The next stage is the addition of the uprights. These are bolted to the horizontal runways and carry the weight of the selectors for which reason each is provided with a large pediment. Assuming that the selectors are constructed as previously described with a common driving shaft for a group of switches, then the uprights such as 94 and 95 may also serve to carry and align the main driving shafts such as 91.

The main driving shaft 91 is divided up into three sections, one per multiple (it being assumed that the top section has not been fitted). The sections are connected by a flexible coupling such as 99, the bottom one connecting direct with the motor I00. Each section has three bearings such as I0], I02 and I03 bolted on to extension arms on the upright, the upper one also containing a thrust bearing to take the weight of the shaft. The extension arms carry the bearings on the side away from the selector, the other side being a flush fit against and supporting the vertical members of the bank. The projecting end of all the rear bank clamp rods are bolted into the angle-iron upright. The position of the nut on each clamp rod determines the relation between the multiple and the shafting and accordingly as each rod is bolted up a gauge corresponding to the selector will he slid into the selector mounting and the nuts adjusted to give the correct clearance.

It will be seen that the methods adopted allow a very flexible method of extending or equipping an exchange. Suppose only one multiple is required on an upright. The angle iron serves the three multiples on the same upright. All the other items however are put in for one multiple only, i. e. the extension arms, bearings, shaft and bank. Should another multiple be required, the bearing shaft and bank etc. can be added without disturbing the existing equipment. This makes it possible to fill up the uprights completely without leaving spare multiples.

The actual arrangement of selectors on the various uprights is such as to give the minimum cabling. Two methods are possible, one, in which all the first selectors occupy certain uprights, second selectors other, and final selectors still more. The second method is that in which first selectors occupy the top multiple on all uprights, second selectors the centre one and final selectors the bottom or vice versa. The second arrangement by spreading a single rank of selectors over a number of shafts, makes the effect of a drive failure of one shaft less important.

The motors can be driven direct from the mains and to overcome the risk of temporary mains failure the motor generator set used for battery charging might be designed to be reversible so that on mains failure, the generator can act as a motor and drive the normal motor now acting as an alternator to provide the 50 cycle current required to energise the roller driving motors.

A pair of sprockets of the bicycle type may be provided to be fitted into the disengaged half of the upper coupling. Since each shaft will be made alike the upper multiple will always contain such a half coupling running light. In the event of a single motor failure, these sprockets would be fitted on.the faulty drive and on an adjacent one and connected by a length of bicycle chain allowing one motor to take the dual load while repairs were being effected.

On large exchanges the driving motors would run continuously, whilst on smaller ones the motors would only start when a call was originated. On these smaller exchanges the one motor might be used todrive the ringer machine and all its associated cams. Such motors are normally of two types, mains-driven normally ing andbat'ter'yniiiven us'e'u as a standby r angemerit for aking'the selector-dink function uite cl-ieap design. H g n ctors ai-e 'previued iridiviiiuaimariach -switch to eliminate: the com'me'n' drive, it wouldthenbe pronablyl desirable ir'i thei-nteres'ts of 'ecenomy to piovide a spjeiai metdr generatorfor tlie ring= ifig' cur tonjes; etc; -:althoug l the-inventionhide the possibility- "of employing the individual motors for producing all tones-neeliie 'done conornically: I

rovided common to: a'n-= upright malnten cc point o'f view a lfiate which: Waldi'gii-uy-prn" in such manner as to engagewith' a,corresp'ond-- ing :pimemon a comrnon -motor driven driving shaft when the switch is jacked into position. The short roller drive-'within*e'achswitch would thus be ;in continuous-rotation so long :as' the switch is jacked in position and-would bac'oiipled up by the friction drivingcams inthe same manner as cou'p'lir'igis"efiectedwiththe common drivingsroller. eacnswitch eould be a sealed imit which-"would beisolditoancustomer assu'ch,'iian"d (which,v f any thing z-went wrong, would 1 bet' returned lto the manufacturer .for repair or readjustment where the best' possible arrangements-Tier adjustment an'd for repair would be available, This ffeature would haverp'articular appeal sameness of private automatic exchanges where skilled maintenance personnel and suitable maintenance equipment are not ordinarily readily available. The sealed cover arrangements would furthermore provide an effective remedy against unnecessary wear and trouble which results from the ingress of dust and abrasives which is always likely to occur when maintenance and equipment are performed on site, as is usual at present.

Subject matter pertaining to the contact bank structure and method of constructing same may be found in the filed divisional applications.

I claim:

1. In a switching exchange layout, a plurality of groups of independently operable switches, means for supporting said switches so that those in the same group are aligned vertically one above another and so that the various groups are arranged in vertical and horizontal rows, each group being situated at the intersection of a particular vertical row and a particular horizontal row, each of said groups having an individual vertical contact multiple to which all switches of that group have access, and horizontal cables for each horizontal row of switch groups interconnecting the individual vertical contact multiples of different groups in that horizontal row.

2. A switching exchange layout as claimed in claim 1, wherein the switches in all groups on one level are selectors and wherein the switches in all groups on another level are connectors.

3. A switching exchange layout as claimed in claim 1, wherein connections are extended through successive switching stages, and wherein filternativly see-enema incorporated in The advantageiobtained is that" are in different switchin'g stages. i'r'ig' exchange iayout as" claimed in ps of f conducting material each extend l'ea's-t from the level cr me lowest; 0'; switch *group to the' lev'el ofthe highestswit and, individual to each switc 1 ductor all t witiithe' respectively corre s 1 D epend'entl yoperable switches, ing said switches so that those e are alignedverti'cally one above that the various groups are ar d a sarticmar horizontal row;

mi n a ting" A those groups, and cables carried by--said runway 3i)"-' H er'corinecting the termini of the vertical horizontal row;

6. A switching exchange layout as claiine'din claini S; wherein eaeh 'h'orizontal' row of "switch wii'erein the runwayior each horizontalrow isat the upperiend of the vertical contact multiples of cthe grcups:in thatahorizontal row; 40"

groups has a different horizontal runway, and wherein the runway for each horizontal row is at the lower end of the vertical contact multiples of the groups in that horizontal row.

8. In a telephone exchange layout, a plurality of outlets, a plurality of groups of switches, switches of the same group having access to the same outlets and switches of different groups having access to different outlets, means for supporting said switches so that those in the same group are aligned vertically one above another and different groups are arranged in vertical and horizontal rows, each group being situated at the intersection of a particular vertical row and a particular horizontal row, and horizontal cables interconnecting outlets of different groups in the same horizontal row.

9. In a switching exchange layout, a plurality of independently operable switches each having access to certain outlets, means for supporting said switches in vertical and horizontal rows, each vertical row comprising a plurality of groups of switches, means connecting the outlets of all switches of each group in multiple without connecting in multiple the outlets of switches of adjacent groups in the same vertical row, and means connecting in multiple the outlets of certain switches in the same horizontal row.

10. In a switching exchange layout, a framework comprising a plurality of runways and a plurality of spaced apart vertical members supporting said runways horizontally and spaced apart one above another, a plurality of vertically elongated contact bank multiples each supported by t e saine switching stage andups are in diiierent honin the vertical contactmultiple grou of switche's' includes a plurality S; switching exchange layout, a' plurality' verticaranunefizontai rows, each group" atth i'fitersecti'oh o'f a particular 3 each oi sai'd g r'oups navingan individual vertical co'n tact multiple to which all switches of" that h V'erti'c all contact 1 multiples he same horizontal row ter 4 orizorit'al runway common to" contact multiples-far difi ernt groups inthe same" 7;: A switchingiexchange layoutlas claimed in claim 5, wherein each horizontal rcwof swit'ch' said framework so that it occupies a position between adjacent vertical members and between adjacent runways with one end of such multiple proximate to one runway, whereby said multiples are arranged in horizontal rows one above another, cables supported on said runways and interconnecting bank multiples whose respective ends are proximate thereto, and a plurality of groups of independently operable switches supported by said framework, said groups corresponding respectively to said contact multiples and the switches of each group having common access to the contact multiple for that group.

11. A switching exchange layout as claimed in claim 10, wherein said switches are mounted upon said framework after said bank multiples and said cables are in place.

12. In an electrical switching system, a plurality of independently operable switches mounted in vertical and horizontal rows, common driving means for the switches in each vertical row, said means including a vertical shaft individual to each vertical row and common to all the switches in that row for transmitting mechanical power to those switches, and a plurality of vertical contact multiples each accessible to a plurality, but not all, of the switches in the same vertical row, whereby difierent groups of switches in the same vertical row have access to diiferent vertical contact multiples.

13. An electrical switching system as claimed in claim 11, wherein each of said switches includes operating members driven by said shaft in a horizontal plane.

14. In an electrical switching system as claimed in claim 11, a plurality of motors each normally driving a single one of said shafts independently of the other shafts, and means for at times coupling adjacent ones of said shafts together so that the coupled shafts will be driven by a single one of said motors.

15. In an electrical switching system, a plurality of independently operable switches mounted in vertical and horizontal rows, each vertical row comprising a plurality of groups of switches, and each of said groups having an individual vertical contact multiple to which all the switches of that group have common access, common driving means for all the switches in each vertical row, said means including a vertical shaft individual to each group of switches for transmitting mechanical power to all the switches in that group, and means mechanically coupling together the shafts for adjacent groups of switches in the same vertical row.

16. A switching system as claimed in claim 15, wherein the shafts respectively individual to different groups of switches in the same vertical row are in vertical alignment with one another.

17. An electrical switching system as claimed in claim 15, wherein connections are extended through successive switching stages, wherein all switches in the same horizontal row are in the same switching stage, and wherein switches in different groups in the same vertical row are in difierent switching stages.

GEORGE THOMAS BAKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,579,026 Owen Mar. 30, 1926 1,725,04e Aldendorfi Aug. 20, 1929 2,218,834 Sengebusch Oct. 22, 1940 2,259,103 Drake Oct. 14, 1941 2,120,980 Johnston June 21, 1938 2,261,412 Reeve Nov. 4, 1941 2,218,833 Sengebusch Oct. 22, 1940 

